140.95=3.14(r)^2

Solution for 140.95=3.14(r)^2 equation:

140.95=3.14(r)^2

We move all terms to the left:

140.95-(3.14(r)^2)=0

We get rid of parentheses

-3.14r^2+140.95=0

a = -3.14; b = 0; c = +140.95;
Δ = b2-4ac
Δ = 02-4·(-3.14)·140.95
Δ = 1770.332
The delta value is higher than zero, so the equation has two solutions
We use following formulas to calculate our solutions:
$r_{1}=\frac{-b-\sqrt{\Delta}}{2a}$
$r_{2}=\frac{-b+\sqrt{\Delta}}{2a}$

$r_{1}=\frac{-b-\sqrt{\Delta}}{2a}=\frac{-(0)-\sqrt{1770.332}}{2*-3.14}=\frac{0-\sqrt{1770.332}}{-6.28}
=-\frac{\sqrt{}}{-6.28}
$
$r_{2}=\frac{-b+\sqrt{\Delta}}{2a}=\frac{-(0)+\sqrt{1770.332}}{2*-3.14}=\frac{0+\sqrt{1770.332}}{-6.28}
=\frac{\sqrt{}}{-6.28}
$